WASHINGTON (7News) — The family of Sudiksha Konanki, a 20-year-old college student from Loudoun County who went missing during a spring break trip in the Dominican Republic, has sent a formal request to police in the Dominican Republic to declare their daughter dead, ABC News reports.

Sources told ABC News that in the letter, the Konanki family said they trust the authorities' investigation and understand that certain legal procedures must be followed for their request. However, they said they are prepared to comply with any necessary documentation.

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The Konanki family also said in the letter that they acknowledge there is no suspicion of foul play, sources told ABC News.

Joshua Riibe, 24, is believed to be the last person to see Konanki before her disappearance and is a person of interest in the case, the Loudoun County Sheriff's Office told 7News.

Riibe has been undergoing questioning by authorities for at least three days and an official close to the investigation told ABC News prosecutors confiscated his passport.

READ MORE | Person of interest's passport confiscated in case of missing student in Dominican Republic

Riibe's lawyers said they've requested a habeas corpus hearing, a source from the Dominican Republic Ministry of Justice told ABC News.

In the Dominican Republic, people can challenge an unlawful detention through a habeas corpus hearing. Detained individuals are required to be brought before a judge within 48 hours, or they must be either charged or released.

As of Monday, Konanki has been missing for 11 days. Konanki was last seen exactly one week ago on the morning of March 6 at the Riu República Hotel in Punta Cana. Police said she disappeared at a beach by the hotel before dawn, as she and other guests had headed outside amid a power outage at the resort.

Interpol has since issued a Yellow Notice --- a global police alert for a missing person, which is often used in cases of unexplained disappearances.